Paxful offers “Peer-to-Peer Exchange Market” for Bitcoin.
It isn’t a place for margin trading of Cryptocurrency(for making profit by difference of market prices), but it is the place where participants can own or disown Bitcoin via methods they like.
By joining Paxful, you can sell your funds(in many form such as cash, gift card, online money etc…) to buy Bitcoin from others. In this case, the seller of Bitcoin needs to accept your offer for the price.
You can also sell Bitcoin for other forms of funds. In this case, you may simply need to find the offers in the market of Paxful.